Battery module and battery pack including same

Abstract

A battery module according to one embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked in one direction; a module frame that houses the battery cell stack and has an inner surface and an outer surface; and an end plate that is coupled to the module frame and covers a front surface or a rear surface of the battery cell stack. The module frame has a vent portion formed therein, and the vent portion includes a concentric pattern portion and a support portion that supports the pattern portion.

Description

[Technical Field]

[0001] [Cross-reference to related applications] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0023581 dated February 22, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a battery module and a battery pack including the same, and more particularly to a battery module with improved safety and a battery pack including the same. [Background technology]

[0003] Technological development and increasing demand for mobile devices have led to a rapid increase in demand for secondary batteries as an energy source. In particular, secondary batteries are attracting much attention as an energy source for mobile devices such as mobile phones, digital cameras, laptops, and wearable devices, as well as for power plants such as electric bicycles, electric vehicles, and hybrid electric vehicles.

[0004] When secondary batteries are primarily used in devices such as mobile equipment, it has been possible to achieve the storage capacity and energy output levels required for each device using one, two, or even four battery cells, but since medium- to large-sized devices such as automobiles require high-output and large-capacity storage devices, using a small number of battery cells as described above can cause significant problems in terms of energy storage capacity and energy output. Therefore, medium- to large-sized devices are generally equipped with a battery module in which a number of battery cells are electrically connected, or a battery pack including a plurality of such battery modules.

[0005] FIG. 1 is an exploded perspective view of a conventional battery module.

[0006] Referring to FIG. 1, a conventional battery module 10 includes a battery cell stack 12 in which a plurality of battery cells 11 are stacked, a module frame 20 for protecting the battery cell stack 12 from external impact, heat, or vibration, and end plates 40 for covering the front and / or rear of the battery cell stack 12.

[0007] The battery cell stack 12 is positioned within a sealed structure formed by the combination of the module frame 20 and the end plates 40. To maximize the energy storage capacity of the battery module 10, the individual battery cells 11 are typically closely spaced within the battery cell stack 12.

[0008] However, this design of the battery module 10 may impair the durability or long-term stability of the battery module 10. Specifically, if the internal pressure of a battery cell 11 increases due to overcharging or other reasons, high-temperature heat, gas, or flame may be released outside the battery cell 11. At this time, the heat, gas, or flame released from one battery cell 11 may be transferred to other adjacent battery cells 11 at close intervals, potentially causing continuous ignition. Furthermore, the heat, gas, or flame released from each battery cell 11 may be released toward an opening formed in the end plate 40, and in this process, problems may occur, such as damage to bus bars (not shown) located between the end plate 40 and the battery cells 11.

[0009] Furthermore, since the plurality of battery modules 10 in the battery pack are arranged so that at least two end plates 40 face each other, if heat, gas, flame, etc. generated within the battery module 10 is discharged to the outside of the battery module 10, it may affect the performance and stability of the plurality of battery cells 11 in other adjacent battery modules 10.

[0010] Therefore, it is necessary to develop a battery module 10 that has improved durability and safety by effectively slowing down the heat propagation speed in the event of an internal fire in the battery module 10 and allowing the generated heat, gas, or flame to be quickly discharged to the outside of the battery module 10. Summary of the Invention [Problem to be solved by the invention]

[0011] The problem to be solved by the present invention is: Another object of the present invention is to provide a battery module that allows gas inside the battery module to quickly escape to the outside, and a battery pack including the battery module. To provide a battery module that effectively suppresses flames when a fire breaks out inside the battery module and effectively discharges internal heat, gas, flames, etc., and a battery pack including the same.

[0012] The problems to be solved by the present invention are not limited to the problems described above, and problems not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from this specification and the accompanying drawings. [Means for solving the problem]

[0013] A battery module according to one embodiment of the present invention includes a battery cell stack in which a plurality of battery cells are stacked in one direction; a module frame that houses the battery cell stack and has an inner surface and an outer surface; and an end plate that is coupled to the module frame and covers a front surface or a rear surface of the battery cell stack. The module frame has a vent portion formed therein, and the vent portion includes a concentric pattern portion and a bar that supports the pattern portion.

[0014] The bar may have an X-shape.

[0015] The vent portion may include at least one hole-shaped vent hole defining an inlet formed on the inner surface of the module frame and an outlet formed on the outer surface.

[0016] The terminal region of the vent hole may have an inverse tapered shape, and the terminal region may be a region including the inlet or the outlet.

[0017] A side surface of the vent hole extending between the inlet and the outlet based on an axial cross section of the vent hole has a rounded shape, and the outflowing matter flowing in through the inlet can move to the outlet along the rounded shape.

[0018] A blocking sheet may be positioned at a portion of the vent corresponding to the inlet.

[0019] The blocking sheet may be made of a material that melts in response to the internal temperature of the module frame.

[0020] The barrier sheet may include one or more selected from the group consisting of inorganic carbonates, inorganic phosphates, and inorganic sulfates.

[0021] When a direction in which the plurality of battery cells are stacked is defined as a stacking direction, the vent may be formed on one surface of the module frame extending along the stacking direction.

[0022] When the direction from the front surface to the rear surface of the battery cell stack is defined as the longitudinal direction, the position of the vent portion in the longitudinal direction may be closer to the front surface or the rear surface of the battery cell stack than a center portion of the battery cell stack that is the same distance in the longitudinal direction as the front surface and the rear surface of the battery cell stack.

[0023] The battery cells may include electrode leads protruding from one end of the battery cells, and the electrode leads may be located on the front or rear surface of the battery cell stack.

[0024] A battery pack according to an embodiment of the present invention includes at least one battery module. [Effects of the Invention]

[0025] According to the embodiment, the vent portion is formed in the module frame, so that flames in the event of a fire inside the battery module can be effectively suppressed and internal gas can be effectively discharged.

[0026] The effects of the present invention are not limited to the effects described above, and any unmentioned effects will be clearly understood by those skilled in the art from this specification and the accompanying drawings. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 10 is an exploded perspective view of a conventional battery module. [Figure 2] 1 is a perspective view of a battery module according to an embodiment of the present invention; [Figure 3] FIG. 3 is an exploded perspective view of the battery module of FIG. 2. [Figure 4] 3 is a diagram showing a battery cell included in the battery module of FIG. 2. FIG. [Figure 5] 3 is a cross-sectional view of the battery module of FIG. 2 taken along line AA. [Figure 6] 4 is a diagram illustrating a direction in which heat, gas, or flame generated in an internal space of a battery module according to an embodiment of the present invention is discharged through a vent portion. [Figure 7] 10A and 10B are diagrams illustrating an example of a vent portion of a battery module according to an embodiment of the present invention. [Figure 8] 10A and 10B are diagrams illustrating a case where a blocking sheet is provided in a vent portion of a battery module according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0028]

[0033] Hereinafter, various embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the embodiments. The present invention may be realized in various different forms other than those described below, and the scope of the present invention is not limited to the embodiments described herein.

[0029] In order to clearly explain the present invention, parts that are not relevant to the description will be omitted, and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0030] Furthermore, the size and thickness of each component shown in the drawings are arbitrarily enlarged or reduced for the sake of convenience, and it is obvious that the contents of the present invention are not limited to those shown. In the following drawings, the thickness of each layer is exaggerated to clearly show multiple layers and regions. In the following drawings, the thickness of some layers and regions is exaggerated for the sake of convenience.

[0031] Furthermore, when a layer, film, region, plate, etc. is described as being "on" or "above" another portion, this should be interpreted as including not only the case where the layer, film, region, plate, etc. is "directly above" the other portion, but also the case where there are other portions therebetween. Conversely, when a layer, film, region, plate, etc. is described as being "directly above" another portion, it means that there are no other portions therebetween. Furthermore, being "on" or "above" a reference portion means being located above or below the reference portion, and does not necessarily mean being located "above" or "above" the opposite direction of gravity. Meanwhile, similar to the description of being "on" or "above" another portion, the description of being "below" or "beneath" another portion can also be understood with reference to the above content.

[0032] Also, throughout the specification, when a part is said to "comprise" a certain element, this means that it may further include other elements, rather than excluding other elements, unless otherwise specified to the contrary.

[0033] Furthermore, throughout the specification, the term "on a plane" means when the relevant part is viewed from above, and the term "on a cross section" means when the relevant part is cut vertically and viewed from the side.

[0034] A battery module according to an embodiment of the present invention will now be described.

[0035] Fig. 2 is a perspective view of a battery module according to an embodiment of the present invention, and Fig. 3 is an exploded perspective view of the battery module of Fig. 2. Fig. 4 is a view showing a battery cell included in the battery module of Fig. 2.

[0036] 2 and 3, a battery module 100 according to an embodiment of the present invention may include a battery cell stack 120 in which a plurality of battery cells 110 are stacked in one direction, a module frame 200 that houses the battery cell stack 120, a bus bar frame 300 that is positioned on the front and / or rear surface of the battery cell stack 120, end plates 400 that cover the front and / or rear surface of the battery cell stack 120, and bus bars 510, 520 that are attached to the bus bar frame 300.

[0037] The battery cells 110 may be provided in a pouch shape, which allows for maximizing the number of cells stacked per unit area. The pouch-shaped battery cells 110 may be manufactured by enclosing an electrode assembly including a positive electrode, a negative electrode, and a separator in a cell case 114 made of a laminate sheet, and then heat-sealing the sealing portion of the cell case 114. However, it is obvious that the battery cells 110 do not necessarily have to be provided in a pouch shape, and may be provided in a prismatic, cylindrical, or other various shapes as long as the storage capacity required by the device to be later installed is achieved.

[0038] 4, the battery cell 110 may include two electrode leads 111 and 112. The electrode leads 111 and 112 may each have a structure that protrudes from one end of the cell body 113. Specifically, one end of each electrode lead 111 and 112 is located inside the battery cell 110 and electrically connected to a positive electrode or a negative electrode of the electrode assembly, and the other end of each electrode lead 111 and 112 is led out of the battery cell 110 and electrically connected to a separate member, for example, bus bars 510 and 520.

[0039] The electrode assembly in the cell case 114 may be sealed by sealing portions 114sa, 114sb, and 114sc. The sealing portions 114sa, 114sb, and 114sc of the cell case 114 may be located on both ends 114a and 114b and one side 114c connecting them.

[0040] The cell casing 114 generally has a laminate structure of a resin layer / metal foil film layer / resin layer. For example, if the surface of the cell casing is made of an O(oriented)-nylon layer, it tends to slip easily due to external impact when stacking a number of battery cells 110 to form a medium- to large-sized battery module 100. Therefore, to prevent this and maintain a stable stacked structure of the battery cells 110, an adhesive member such as a pressure-sensitive adhesive such as double-sided tape or a chemical adhesive that bonds through a chemical reaction when bonded can be attached to the surface of the cell casing 114 to form the battery cell stack 120.

[0041] The connecting portion 115 refers to a region extending along the longitudinal direction at one end of the cell casing 114 where the sealing portions 114sa, 114sb, and 114sc are not located. A protruding portion 110p of the battery cell 110, called a butt ear, may be formed at the end of the connecting portion 115. In addition, the terrace portion 116 refers to a region between the electrode leads 111 and 112, some of which protrude outside the cell casing 114, and the cell body 113 located inside the cell casing 114, based on the edge of the cell casing 114.

[0042] Meanwhile, the battery cell 110 provided in a pouch shape may have a length, width, and thickness, and the length direction, width direction, and thickness direction of the battery cell 110 may be perpendicular to each other.

[0043] Here, the longitudinal direction of the battery cell 110 may be defined as the direction in which the electrode leads 111 and 112 protrude from the cell casing 114. For example, one electrode lead 111 may protrude in one direction (x-axis direction) from one end 114a of the cell casing 114, and the other electrode lead 112 may protrude in the opposite direction (-x-axis direction) from one end 114b of the cell casing 114. In this case, the longitudinal direction of the battery cell 110 may be defined as the x-axis direction or the -x-axis direction.

[0044] 4, the width direction of the battery cell 110 may be the z-axis direction or the -z-axis direction from one side 114c of the battery cell 110 to the connecting part 115 or from the connecting part 115 to one side 114c. The thickness direction of the battery cell 110 may be defined as the y-axis direction or the -y-axis direction that is perpendicular to the width direction and the length direction.

[0045] Meanwhile, although the longitudinal direction, width direction, and thickness direction have been described above based on the axial direction shown in the drawings, this is merely for the convenience of explanation, and the thickness direction, longitudinal direction, and width direction described above may be defined differently from the drawings depending on the structure of the battery cell 110.

[0046] The battery cell stack 120 may be formed by stacking a plurality of electrically connected battery cells 110 in one direction. The direction in which the plurality of battery cells 110 are stacked (hereinafter referred to as the "stacking direction") may be the y-axis direction (or the -y-axis direction, and hereinafter the term "axis" will be interpreted as including both + and - directions) as shown in Figures 2 and 3.

[0047] Here, the stacking direction of the battery cell stack 120 may be the thickness direction of the battery cells 110. This is because the thickness of the battery cells 110 is designed to be smaller than the length and width of the battery cells 110, and when the battery cells 110 are stacked in the above-mentioned direction, their volume can be minimized. Therefore, it should not be construed that the stacking direction of the battery cell stack 120 and the thickness direction of the battery cells 110 are always the same, and the stacking direction may be determined depending on the shape of the battery cells 110.

[0048] The battery cell stack 120 may have an overall shape similar to a rectangular parallelepiped. Each face of the battery cell stack 120 may be defined by the stacking direction (y-axis direction).

[0049] For example, two surfaces of the battery cell stack 120 that face each other in the stacking direction may be defined as side surfaces of the battery cell stack 120. One surface of one battery cell 110 having a length and a width may be located on the side surface of the battery cell stack 120.

[0050] Furthermore, surfaces of the battery cell stack 120 that face each other on an axis perpendicular to the stacking direction may be defined as the front / rear surface or the top / bottom surface. The front, rear, top, or bottom surface of the battery cell stack 120 may be surfaces that extend along the stacking direction of the battery cell stack 120. One surface of a plurality of battery cells 110 may be positioned side by side on the front, rear, top, and bottom surfaces of the battery cell stack 120. Here, one surface of the battery cells 110 positioned side by side may be a surface parallel to the thickness direction.

[0051] The direction from the front surface to the rear surface of the battery cell stack 120, or the reverse direction, may be defined as the longitudinal direction of the battery cell stack 120, which may be the x-axis direction. Furthermore, the direction from the top surface to the bottom surface of the battery cell stack 120, or the reverse direction, may be defined as the width direction of the battery cell stack 120, which may be the z-axis direction.

[0052] The longitudinal direction of the battery cell stack 120 may be substantially the same as the longitudinal direction of the battery cells 110. The electrode leads 111, 112 of the battery cells 110 may be located on the front and rear surfaces of the battery cell stack 120. When the electrode leads 111, 112 of each battery cell 110 are concentrated on the front and rear surfaces of the battery cell stack 120 as shown in FIG. 3 , the bus bars 510, 520 of the battery module 100 may be designed to be located close to the front and rear surfaces of the battery cell stack 120. This allows the bus bars 510, 520 to more easily provide electrical connection between the electrode leads 111, 112 located inside the battery module 100 and electrical components located outside the battery module 100.

[0053] The battery cell stack 120 may include a peripheral region 120a and a central region 120b defined by their positions in the longitudinal direction. Specifically, the battery cell stack 120 may include the central region 120b including a central surface (or center) spaced the same distance as the front and rear surfaces of the battery cell stack 120, and the peripheral region 120a spaced apart from the central region. Here, the peripheral region 120a may be located closer to the bus bar frame 300, end plates 400, and bus bars 510 and 520 (described below) than the central region 120b. Here, the peripheral region 120a may include the region where the electrode leads 111 and 112 are located, but this is not necessarily the case.

[0054] The module frame 200 may be configured to protect the battery cell stack 120 and the electrical components connected thereto from external physical impacts. The module frame 200 may accommodate the battery cell stack 120 and the electrical components connected thereto in an internal space of the module frame 200. Here, the module frame 200 includes an internal surface (see FIG. 5, 200a) and an external surface (see FIG. 5, 200b), and the internal space of the module frame 200 may be defined by the internal surface 200a.

[0055] The module frame 200 may have a variety of structures. As an example, the module frame 200 may have a mono-frame structure. Here, the mono-frame may be in the form of a metal plate with an integrated top, bottom, and both side surfaces. The mono-frame may be manufactured by extrusion molding. As another example, the module frame 200 may have a structure in which a U-shaped frame and an upper plate are combined. In the case of a structure in which a U-shaped frame and an upper plate are combined, the module frame 200 may be formed by combining the upper plate with the upper part of a U-shaped frame, which is a metal plate with an integrated or combined bottom and both side surfaces, and each frame or plate may be manufactured by press molding. Furthermore, the module frame 200 may have an L-shaped frame structure in addition to a mono-frame or U-shaped frame, and may have various structures not described in the above examples.

[0056] The module frame 200 may be provided with an open structure along the longitudinal direction of the battery cell stack 120. The front and rear surfaces of the battery cell stack 120 are not hidden by the module frame 200. The electrode leads 111, 112 of the battery cells 110 are not hidden by the module frame 200. The front and rear surfaces of the battery cell stack 120 are hidden by the bus bar frame 300, end plate 400, or bus bars 510, 520, which will be described later, and thus the front and rear surfaces of the battery cell stack 120 can be protected from external physical impacts, etc.

[0057] Meanwhile, a compression pad 150 may be positioned between the battery cell stack 120 and one side of the inner surface of the module frame 200. In this case, the compression pad 150 may be positioned on the y-axis of the battery cell stack 120 and may face at least one of the two battery cells 110 at both ends of the battery cell stack 120.

[0058] Although not shown in the drawings, a thermally conductive resin may be injected between the inner surfaces of the battery cell stack 120 and the module frame 200, and the injected thermally conductive resin may form a thermally conductive resin layer (not shown) between one side of the inner surfaces of the battery cell stack 120 and the module frame 200. In this case, the thermally conductive resin layer may be located on the z-axis of the battery cell stack 120, and the thermally conductive resin layer may be formed between the battery cell stack 120 and a bottom surface (also referred to as a bottom) located on the -z-axis of the module frame 200.

[0059] The bus bar frame 300 may be positioned on one side of the battery cell stack 120 to cover that side and guide the connection of the battery cell stack 120 to an external device. The bus bar frame 300 may be positioned on the front or rear side of the battery cell stack 120. At least one of bus bars 510, 520 and a module connector is attached to the bus bar frame 300. For a specific example, referring to FIGS. 2 and 3 , one side of the bus bar frame 300 may be connected to the front or rear side of the battery cell stack 120, and the other side of the bus bar frame 300 may be connected to the bus bars 510, 520.

[0060] The bus bar frame 300 may include an electrically insulating material. The bus bar frame 300 can limit contact between the bus bars 510 and 520 and other parts of the battery cells 110 other than the parts joined to the electrode leads 111 and 112, thereby preventing an electrical short circuit from occurring.

[0061] Although not shown in the drawings, there may be two bus bar frames 300, including a first bus bar frame located on the front surface of the battery cell stack 120 and a second bus bar frame located on the rear surface of the battery cell stack 120.

[0062] The end plates 400 may serve to protect the battery cell stack 120 and the electrical components connected thereto from external physical impact by sealing the open side of the module frame 200. To this end, the end plates 400 may be made of a material having a predetermined strength. For example, the end plates 400 may include a metal such as aluminum.

[0063] The end plate 400 can be coupled (joined, sealed, or sealed) to the module frame 200 by covering the bus bar frame 300 or the bus bars 510, 520 located on one side of the battery cell stack 120. Each edge of the end plate 400 can be coupled to a corresponding edge of the module frame 200 by a method such as welding. In addition, an insulating cover 800 for electrical node insulation can be positioned between the end plate 400 and the bus bar frame 300.

[0064] Although not shown in the drawings, there may be two end plates 400, including a first end plate located on the front surface of the battery cell stack 120 and a second end plate located on the rear surface of the battery cell stack 120.

[0065] The first end plate may be coupled to the module frame 200 by covering the first bus bar frame on the front surface of the battery cell stack 120, and the second end plate may be coupled to the module frame 200 by covering the second bus bar frame. In other words, the first bus bar frame may be located between the first end plate and the front surface of the battery cell stack 120, and the second bus bar frame may be located between the second end plate and the rear surface of the battery cell stack 120.

[0066] The bus bars 510 and 520 may be attached to one surface of the bus bar frame 300 and may be used to electrically connect the battery cell stack 120 or the battery cells 110 to an external device circuit. By being located on the battery cell stack 120 or the bus bar frame 300 and the end plate 400, the bus bars 510 and 520 may be protected from external impacts and minimize deterioration in durability due to external moisture.

[0067] The bus bars 510 and 520 may be electrically connected to the battery cell stack 120 via the electrode leads 111 and 112 of the battery cells 110. Specifically, the electrode leads 111 and 112 of the battery cells 110 may pass through slits formed in the bus bar frame 300 and then bend to be connected to the bus bars 510 and 520. The bus bars 510 and 520 may connect the battery cells 110 constituting the battery cell stack 120 in series or parallel.

[0068] The bus bars 510 and 520 may include a terminal bus bar 520 for electrically connecting one battery module 100 to another battery module 100. At least a portion of the terminal bus bar 520 may be exposed to the outside of the end plate 400 to be connected to another external battery module 100, and the end plate 400 may be provided with a terminal bus bar opening 400H for this purpose.

[0069] Unlike the other bus bars 510, the terminal bus bar 520 may further include a protruding portion that protrudes upward, and the protruding portion may be exposed to the outside of the battery module 100 through the terminal bus bar opening 400H. The terminal bus bar 520 may be connected to other battery modules 100 or a BDU (Battery Disconnect Unit) through the protruding portion exposed through the terminal bus bar opening 400H, and may form an HV (High Voltage) connection therewith.

[0070] Meanwhile, as described above, a fire may occur inside a battery module 100 in which battery cells 110 are stacked at a high density. If a fire occurs in one battery module 100, heat, gas, or flames from the battery module 100 may be transferred to the adjacent battery modules 100, which may result in continuous fires between the battery modules 100. This may result in a decrease in the durability and stability of the battery modules 100 or a battery pack including the battery modules 100.

[0071] Therefore, the following will describe a venting part 210 that can improve the durability and stability of the battery module 100 by eliminating the above-mentioned ignition phenomenon.

[0072] FIG. 5 is a cross-sectional view of the battery module of FIG. 2 cut along line AA, FIG. 6 is a view showing the direction in which heat, gas, or flames generated in the internal space of a battery module according to one embodiment of the present invention are discharged through a vent, and FIG. 7 is a view showing an example of a vent of a battery module according to one embodiment of the present invention.

[0073] 5 and 6, a module frame 200 according to one embodiment of the present invention may include a vent 210 extending through an interior surface 200a and an exterior surface 200b of the module frame 200.

[0074] The vent portion 210 may be configured to communicate the inside of the battery module 100, which is sealed by the module frame 200 and the end plate 400, with the outside of the battery module 100. The vent portion 210 may be configured to exhaust heat, gas, flames, etc. generated when the battery module 100 is ignited inside the battery module 100, to the outside of the battery module 100.

[0075] Meanwhile, when the module frame 200 is provided with a vent 210 for communicating the inside with the outside, dust, impurities, etc. from the outside of the module frame 200 may enter the inside of the module frame 200 through the hole structure of the vent 210. Therefore, in order to prevent foreign matter from entering through the hole of the vent 210, it is preferable that the hole size of the vent 210 is small.

[0076] Therefore, the vent portion 210 according to an embodiment of the present invention may be designed to include a number of small holes. Here, the holes in the vent portion 210 are referred to as vent holes 211, and the size of the vent holes 211 may be determined by the pattern portion 212 included in the vent portion 210 and the support portion 214 for supporting the pattern portion 212. In this case, the pattern portion 212 is interpreted as including the support portion 214, but for convenience of explanation, they will be described separately below.

[0077] The vent section 210 may include a vent hole 211 that communicates an inlet (210a) formed on the inner surface 200a of the module frame 200 and an outlet (210b) formed on the outer surface 200b. A hole-inlet 211a of the vent hole 211 may be located at the inlet 210a of the vent section 210, and a hole-outlet 211b of the vent hole 211 may be located at the outlet 210b of the vent section 210. The hole-inlet 211a, the hole-outlet 211b, and a hole-side surface 211c extending between the hole-inlet 211a and the hole-outlet 211b may be defined by the vent hole 211.

[0078] The vent portion 210 may include a pattern portion 212 having a concentric pattern shape and a support portion 214 for supporting the shape of the pattern portion 212. Based on the radial cross section of the vent portion 210, the pattern portion 212 may include multiple shapes that are aligned at the same center and spaced apart radially. Furthermore, based on the radial cross section of the vent portion 210, the support portion 214 may be provided in the form of a bar and may support the multiple shapes included in the pattern portion 212. The shapes of the pattern portion 212 may be connected to each other by the support portion 214, and the overall pattern shape of the pattern portion 212 may be maintained by the support portion 214.

[0079] The shape, size, position or number of the vent holes 211 may be determined by the pattern shape of the pattern portion 212 and the shape of the support portion 214 crossing the pattern portion 212 .

[0080] Since the overall shape of the vent hole 211 is mainly determined by the shape of the pattern portion 212, in describing the shape of the vent hole 211, the following description will omit the support portion 214 and focus on the shape of the vent hole 211 defined by the pattern portion 212.

[0081] The shape of the vent hole 211 may be a tube shape or a portion of a tube shape, and here, the hole-side surface 211c of the vent hole 211, which corresponds to the cylindrical surface of the tube shape, may be mainly defined by the wall surface - or side surface - 212c of the pattern portion 212.

[0082] Meanwhile, the vent hole 211 may have a tubular shape as shown in Figure 6(a), but may also have a deformed tubular shape as shown in Figures 6(b) and 6(c). Here, a deformed tubular shape means that the size and shape of the radial cross section are not constant, and at least a portion of the cylindrical surface is deformed into a convex or concave shape in the radial direction. In a normal tubular shape, the axial cross section may be angular, but in a deformed tubular shape, the axial cross section may be rounded.

[0083] For example, the vent hole 211 may have a shape in which its radial cross section (or diameter) increases toward the axial end, like the constricted portion of a gourd. As shown in Figures 6(b) and 6(c), the end region of the vent hole 211 may have a shape that widens radially outward. The end region of the vent hole 211 may have a reverse tapered shape. Here, the end region of the vent hole 211 may refer to the region located at the end of the axis of the vent hole 211, and the central region of the vent hole 211 may refer to the region located between the two end regions.

[0084] The reverse tapered shape of the vent hole 211 may be formed by curving a portion of the wall surface 212c of the pattern portion 212. In this case, the wall surface 212c of the pattern portion 212 may have a rounded shape in an axial cross section of the vent portion 210. The edge portion 212ca of the vent portion 210, which corresponds to the reverse tapered shape, may also have a rounded shape. Here, the edge portion 212ca may refer to a portion between the lower surface 212a (or referred to as the inlet surface) of the pattern portion 212 located at the inlet 210a and the wall surface 212c of the pattern portion 212.

[0085] If the two end regions of the vent hole 211 have an inverse tapered shape, gases and the like inside the battery module 100 can quickly migrate to the outside of the battery module 100 through the vent hole 211. Specifically, the central region located between the two end regions may have a relatively smaller volume per unit length on the axis than the end regions. Gases and the like can enter the central region through one end region close to the hole inlet 211a, and their pressure can increase due to the volume reduction, allowing them to quickly migrate to the other end region close to the hole outlet 211b, which has a relatively low-pressure environment. This allows gases inside the battery module 100 to quickly migrate to the outside.

[0086] In addition, although the above-described drawings show the case where both end regions of the vent hole 211 have an inverse tapered shape, only one of the end regions of the vent hole 211 may have an inverse tapered shape. Even if only one of the end regions of the vent hole 211 has an inverse tapered shape, it can still promote gas outflow more than a normal tube shape, so the gas discharge effect of the vent holes 211 provided as shown in Figures 6(b) and 6(c) is greater than that of the vent hole 211 provided as shown in Figure 6(a).

[0087] On the other hand, if the edge portion 212ca has a square shape and the vent hole 211 is provided in a tube shape as shown in FIG. 6(a), the internal gas may collide with the edge portion 212ca in the process of discharging heat, gas, flame, etc. from inside the battery module 100 to the outside, and the collided gas may re-enter the inside of the battery module 100, hindering the ventilation function of the vent portion 210.

[0088] On the other hand, if the edge portion 212ca has a rounded shape and the vent hole 211 is provided with an inverted tapered shape as shown in Figures 6(b) and 6(c), internal gases that collide with the edge portion 212ca can move toward the hole-exhaust port 211b in the direction guided by the rounded shape of the edge portion 212ca.

[0089] As described above, the shape of the edge portion 212ca near the inlet 210a forms a path for gases and the like to be exhausted. Therefore, the ventilation effect of the vent portion 210 varies depending on the angle (hereinafter referred to as the "diffraction angle") that the edge portion 212ca forms with the inlet 210a relative to the axial cross section of the vent portion 210. The diffraction angle in FIG. 6(b) can be explained from FIG. 6(a) and FIG. 6(c) is larger than that in FIG. 6(b). In this case, the diffraction angle can be calculated based on a tangent line at a point on the edge portion 212ca. The larger the diffraction angle, the better the ventilation function of the vent portion 210. However, the ventilation function also depends on the size of the rounded shape of the edge portion 212ca and the diameter of the central region of the vent hole 211. Therefore, the greater the diffraction angle, the better the ventilation function of the vent portion 210.

[0090] The vent portion 210 may be formed on at least one surface of the module frame 200. Here, the module frame 200 may have two open surfaces that are arranged to face each other on the x-axis, which is the longitudinal direction of the battery cell stack 120. The module frame 200 may have two surfaces that are arranged to face each other on the y-axis (hereinafter referred to as "y-axis surfaces") and two surfaces that are arranged to face each other on the z-axis (hereinafter referred to as "z-axis surfaces").

[0091] Here, the surface of the module frame 200 on the y-axis may face a side surface of the battery cell stack 120. One surface of the module frame 200 on the y-axis may be a surface extending along the width direction or length direction of the battery cell stack 120. One surface of the module frame 200 on the y-axis may face one surface of one battery cell 110. For ease of explanation, one surface of the module frame 200 on the y-axis will be referred to as a side surface of the module frame 200.

[0092] Also, here, one surface of the module frame 200 on the z-axis may face the top or bottom surface of the battery cell stack 120. One surface of the module frame 200 on the z-axis may be a surface extending along the stacking direction or longitudinal direction of the battery cell stack 120. One surface of the module frame 200 on the z-axis may face one surface of each of the multiple battery cell stacks 120 arranged in a line along one direction. For ease of explanation, one surface of the module frame 200 on the z-axis may also be referred to as the top or bottom surface (bottom surface or bottom portion).

[0093] 5 and 6, the vent portion 210 is preferably formed on one surface of the module frame 200 on the z-axis. This is because when the vent portion 210 is located on one surface of the module frame 200 on the z-axis, the inlet 210a of the vent portion 210 can be positioned closer to the multiple battery cells 110 of the battery cell stack 120 than when the vent portion 210 is located on one surface of the module frame 200 on the y-axis, allowing heat, gas, or flames emitted from the multiple battery cells 110 to be quickly discharged to the outside. In this way, the position of the vent portion 210 on the module frame 200 can be determined by the position of one surface of the battery cell stack 120 where one surfaces of the multiple battery cells 110 are positioned side by side.

[0094] Meanwhile, the position of the vent portion 210 on the module frame 200 may be determined depending on the arrangement of the battery modules 100 within the battery pack. For example, multiple battery modules 100 may be arranged along the y-axis or x-axis within the battery pack, but not along the z-axis. In this case, if the vent portion 210 is formed on one surface of the module frame 200 on the z-axis as shown in Figures 5 and 6, other adjacent battery modules 100 will not be located on the exhaust path extending from the inlet 210a of the vent portion 210 to the outlet 210b, thereby minimizing the impact of exhausted heat, gas, or flame on other battery modules 100. Meanwhile, if the surface on the -z-axis of the two surfaces on the z-axis is the mounting surface (or bottom surface) that is connected to the battery pack, the vent portion 210 is formed on the +z-axis.

[0095] The vent portion 210 may be formed on the entire surface of the module frame 200 or on a portion of the surface of the module frame 200. When the vent portion 210 is formed on a portion of the surface of the module frame 200, the vent portion 210 is preferably located on the periphery of the module frame 200. Specifically, if high-temperature gas or flame is generated from a battery cell 110, the high-temperature gas or flame may be transferred to an adjacent battery module 100 through the terminal bus bar opening 400H, etc., thereby reducing the performance of the adjacent battery module 100. Furthermore, if the flame is directly discharged, the flame may also be transferred to the adjacent battery module, resulting in a chain reaction of fire and explosion. Therefore, when the vent portion 210 is formed on the periphery of the module frame 200 near the bus bar frame 300, the end plate 400, and the bus bars 510 and 520, the vent portion 210 can eliminate a fire within the corresponding battery module 100, thereby minimizing the impact of heat, gas, or flame on other battery modules 100. Also, the vent portion 210 may be provided at a longitudinal position corresponding to the peripheral region of the electrode leads 111, 112 included in the battery cell stack 120. In this case, heat, gas, or flames generated in the peripheral region of the electrode leads 111, 112 can be more effectively discharged through the vent portion 210. Here, the peripheral region of the electrode leads 111, 112 refers to a region including the electrode leads 111, 112 and spaced a predetermined distance or less from the electrode leads 111, 112.

[0096] In this case, the peripheral portion of the module frame 200 refers to the portion of the module frame 200 that corresponds to the peripheral region 120a of the battery cell stack 120, based on the battery module 100 that is assembled as a completed assembly. Here, the peripheral region 120a of the battery cell stack 120 may include the peripheral regions of the electrode leads 111, 112, but this is not necessarily the case. In addition, in this case, the center of the module frame 200 refers to the portion of the module frame 200 that corresponds to the central region 120b of the battery cell stack 120.

[0097] 2 to 6 illustrate the case where there is one vent portion 210, but this is not necessarily the case, and the number of vent portions 210 may vary. As an example, there may be two vent portions 210, and the vent portions 210 may be positioned facing each other at both ends of the module frame 200 in the longitudinal direction. In this case, the vent portions 210 may be provided in positions corresponding to the peripheral regions 120a of the battery cell stack 120. As another example, there may be two or more vent portions 210, and the vent portions 210 may be arranged in rows or columns. The vent portions 210 arranged in rows or columns may be spaced apart, and it is preferable that the spacing between the vent portions 210 be uniform to effectively exhaust gas from within the battery module 100.

[0098] In this case, the direction in which the rows are arranged may be along the longitudinal direction (x-axis direction) of the battery cell stack 120. Also, the direction in which the columns are arranged may be along a direction perpendicular to the longitudinal direction of the battery cell stack 120 (y-axis direction or z-axis direction).

[0099] The vent portion 210 may have a variety of shapes. In the above-described FIGS. 2 through 6, the pattern portion 212 of the vent portion 210 has a concentric circular pattern, and the support portion 214 has an X-shaped bar shape. However, as shown in FIG. 7(a), which illustrates an example of a vent portion 210 provided in region B, the support portion 214 may be an X-shaped bar consisting of at least two bars, or a linear bar consisting of a single bar, as shown in FIG. 7(b). A linear bar has the advantage of being able to form a large vent hole 211, but it has the disadvantage of not being able to firmly support the pattern portion 212. Furthermore, the pattern portion 212 may have a concentric circular pattern as shown in FIGS. 7(a) and 7(b), a concentric polygonal pattern with coaxial centers as shown in FIG. 7(c), or a concentric geometric pattern with coaxial centers as shown in FIG. 7(d). The geometric patterns of the vent portion 210 may be different from those described above, and the shapes are not limited by the illustrated drawings.

[0100] Meanwhile, the direction in which gas inside the battery module 100 is discharged to the outside through the vent portion 210 may be from the hole-inlet 211a to the hole-outlet 211b, and the direction of the heat, gas or flame discharged from the vent portion 210 can be adjusted by changing the positions of the hole-inlet 211a and the hole-outlet 211b of the vent hole 211.

[0101] When the hole inlet 211a and the hole outlet 211b on the z-axis are formed at different positions in the longitudinal direction (x-axis direction) or the stacking direction (y-axis direction), the discharge direction forms an angle with the direction from the battery cell stack 120 toward the hole inlet 211a. As a result, the direction of high-temperature heat, gas, and flames flowing in from the battery cell stack 120 may be redirected, and the length of their discharge path may be increased, so that the gas discharged through the hole outlet 211b may have a slightly lower temperature.

[0102] In addition, the hole inlet 211a and the hole outlet 211b are formed so that the exhaust direction of the vent portion 210 forms an angle with the direction in which the surface of the module frame 200 on which the vent portion 210 is formed is located, which may be to minimize an influence on adjacent battery modules 100 within the battery pack. Specifically, a plurality of battery modules 100 may be arranged along the x-axis direction within the battery pack, and in this case, the vent portion 210 may be formed on one surface of the module frame 200 located on the x-axis for various reasons, such as design. If the vent portion 210 is located on the x-axis, it is likely to affect other adjacent battery modules 100. Therefore, it is preferable that the exhaust path of the vent portion 210 forms an angle with the x-axis, more specifically, that the exhaust path of the vent portion 210 be formed in a direction in which adjacent battery modules 100 are not located.

[0103] Here, since it is preferable that the heat, gas or flame discharged from the vent portion 210 be diffused more quickly to the outside of the battery module 100, the size of the hole-exhaust port 211b can be provided larger than the size of the hole-inlet port 211a.

[0104] FIG. 8 is a view showing a case where a blocking sheet is provided at a vent portion of a battery module according to an embodiment of the present invention.

[0105] Referring to FIG. 8 , a blocking sheet 220 may be disposed in a portion corresponding to the inlet 210a of the vent portion 210 to cover the hole of the vent portion 210. The blocking sheet 220 may prevent foreign matter from entering from the outside through the vent hole 211. The blocking sheet 220 may also include a material for mitigating ignition in the event of an internal fire in the battery module 100. Here, the blocking sheet 220 may be provided as a material that melts above a certain temperature or pressure. In the event of an internal fire in the battery module 100, the blocking sheet 220 may open the vent hole 211, allowing heat, gas, or flames to be discharged through the vent hole 211. For example, the blocking sheet 220 may be provided as a PF film. As another example, the blocking sheet 220 may include an extinguishing agent that can suppress a combustion reaction by releasing carbon dioxide gas. When the blocking sheet 220 includes an extinguishing agent, the battery module 100 may have a self-extinguishing function. Specifically, in the event of an internal fire in the battery module 100, the fire extinguishing agent can reduce the effects of heat, gas, or flames inside the battery module 100, thereby preventing or delaying continuous fires inside or between the battery modules 100. The insulating sheet 220 may contain one or more fire extinguishing agents selected from the group consisting of inorganic carbonates, inorganic phosphates, and inorganic sulfates. However, the fire extinguishing agents contained in the insulating sheet 220 of the present invention are not limited to the above examples.

[0106] The battery module 100 may be included in a battery pack. The battery pack may include one or more battery modules according to the present embodiment, and may further include a battery management system (BMS) for managing the temperature and voltage of the battery, a cooling device, and the like.

[0107] Within a battery pack, the battery modules 100 may be arranged in rows. For example, a battery module 100 may be arranged with its end plate 400 facing another battery module 100. With reference to the positions of the end plates 400 in the above-described drawings, it may be understood that at least two battery modules 100 are arranged along the longitudinal direction (x-axis direction). As another example, the battery modules 100 may be arranged along the y-axis or z-axis in addition to different x-axes. The stacking direction of the battery modules 100 within a battery pack may vary depending on the volume and shape of the battery pack or the internal structure of the device to which the battery pack is attached, and therefore the stacking direction of the battery modules 100 may differ from the above-described example.

[0108] At this time, the position of the vent 210 and the direction of exhaust from the vent 210 may be determined to prevent continuous ignition between the battery modules 100 within the battery pack. Specifically, the position and direction of exhaust from the vent 210 included in one battery module 100 may be designed not to face another adjacent battery module 100. More detailed information regarding this may be described with reference to the above description.

[0109] The battery module and the battery pack including the same can be applied to various devices, including transportation means such as electric bicycles, electric cars, and hybrid cars, but the present invention is not limited thereto and can be applied to various devices that can use the battery module and the battery pack including the same, which also fall within the scope of the present invention.

[0110] Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements made by those skilled in the art using the basic concept of the present invention defined in the following claims also fall within the scope of the present invention. [Explanation of symbols]

[0111] 100 battery modules 110 battery cells 120 Battery cell stack 200 Module Frame 210 Vent 210a Inlet 210b Outlet 211 Vent Hole 212 Pattern section 214 Support part 220 Blocking Sheet 300 Busbar Frame 400 End Plate 510 Busbar 520 Terminal Busbar

Claims

1. a battery cell stack in which a plurality of battery cells are stacked in one direction; a module frame housing the battery cell stack and having an interior surface and an exterior surface; an end plate coupled to the module frame to cover a front surface or a rear surface of the battery cell stack; a vent portion is formed in the module frame; the vent portion includes a plurality of hole-shaped vent holes defining an inlet formed on the inner surface of the module frame and an outlet formed on the outer surface, the plurality of vent holes collectively forming a concentric pattern, and a portion where no vent holes are formed functions as a support portion supporting the concentric pattern; A side surface of the vent hole extending between the inlet and the outlet has a rounded shape based on an axial cross section of the vent hole, the plurality of vent holes are formed such that, in a plan view of the module frame, the position of the inlet on the inner surface and the position of the outlet on the outer surface are different from each other, so that a discharge path for vent gas forms an angle with a direction from the battery cell stack toward the inlet of the vent hole and is formed in a direction in which an adjacent battery module is not located.

2. The battery module according to claim 1 , wherein the support portion has an X-shape.

3. 3. The battery module according to claim 1, wherein the vent hole has one end region including the inlet, the other end region including the outlet, and a central region located between the two end regions in the longitudinal direction of the vent hole, and the central region has a relatively smaller volume per unit length on the axis than at least one of the two end regions.

4. The battery module according to claim 3 , wherein the outflowing matter flowing in through the inlet moves to the outlet along the round shape.

5. The battery module according to any one of claims 1 to 4, wherein a blocking sheet is positioned at a portion of the vent corresponding to the inlet.

6. The battery module of claim 5 , wherein the blocking sheet is made of a material that melts in response to an internal temperature of the module frame.

7. 7. The battery module according to claim 5, wherein the isolation sheet comprises at least one selected from the group consisting of inorganic carbonates, inorganic phosphates, and inorganic sulfates.

8. When the direction in which the plurality of battery cells are stacked is defined as the stacking direction, 8. The battery module according to claim 1, wherein the vent portion is formed on one surface of the module frame extending along the stacking direction.

9. When the direction from the front surface to the rear surface of the battery cell stack is defined as the longitudinal direction, 9. The battery module according to claim 1, wherein a position of the vent portion in the longitudinal direction is closer to the front surface or the rear surface of the battery cell stack than a center of the battery cell stack that is the same distance in the longitudinal direction as the front surface and the rear surface of the battery cell stack.

10. 10. The battery module according to claim 1, wherein the battery cells include electrode leads protruding from one end of the battery cells, the electrode leads being located on a front surface or a rear surface of the battery cell stack.

11. A battery pack comprising at least one battery module according to any one of claims 1 to 10.

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